Piston



Jan. 19, 1932. s. D. HAR-roe PISTON Filed Jan. 11, 192s Yportion is Petented .lea 19, 1932 l UNITED STATI-:s .PATEN T OFFICE Application mea January '11.;1928. eserial iro. crassa.

This invention relates to pistons. An object of the invention is to provide an improved piston having a skirt and a head that are circumferentially disconnected 5 and that are integrally united by ribs having their lower ends united'to the skirt relatively a considerable distance below the top and having their upper ends unitedk with the piston head portion and being intermediate- 10 1y disconnected from both parts of the piston.

Another object of the invention is to provide an improved piston embodying the structure mentioned Aand in which the head designed and adapted to carry one 'or more piston rings.

Another object of he invention is to pro-l vide an improved piston embodying the structure first stated and in which the skirt of the piston is resiliently expensible when heated to form close contact all around withthe cylinder wall.

Other objects will appear from the followingdescription, reference being made to the drawingsin which l F ig. 1 is a side elevation of my improved piston showing one of the slits in the skirt.

Fig. 2 is another side elevation showing one of the Webs connecting-the skirt with the head portion of the piston and designed and adapted for connection with a piston pin.

Fig. 3 is a vertical sectional yView taken parallel with the axis of the piston pin bosses.

Fig. 4 is aninverted end view of the piston.

In the embodiment of the invention shown my improved piston is a casting comprising a head plate 1 having a depending annular portion .2 provided with a number of c1rcumferential grooves 3 for the reception of piston rings; a.- skirt 4 separated from theone-third of the length of the skirt and extend inwardly and upwardly and thence outwardly to integral union with the annular 41 portion 2 of the head of the piston, having strengthenir g webs 7 running all the way the webs 6 permit the head a point above the lower end of the skirtaboutup to integral merger with the head l. Bosses 8 extending outwardly from the webs 6 in diametrically opposite alinement and are bored to receive a piston pin.

The skirt is provided with a pair of diametrically opposite slits 9 extending upwardly from the lower ends and terminating in enlarged openings 10 having an appropriate relationship to the piston pin bosses. In the embodiment yshown the openings 10 are slightly below the plane of the piston pin bores in the bosses,vthus extending the slits slightly more than half of th'e vertical length of the skirt. This construction in which the webs 6 are wholly disconnected lfrom the skirt of the iston, except at their lower ends, leaves the tractible, the piston that will .maintain yielding contact with the cylinder walls forrelatively a rt freelyexpansible and conthus providing a guide section for v considerable portion of the length of the piston.' The openings in the side walls of the than it otherwise could expand. Moreover, portion of the pis'- ton to expandquite extensively without appreciable effect upon the skirt guide section. This is because the form of the webs provides a ivotal point or fulcrum at a, position slig tly in advance of their intersection with the skirt or guide portion and permits the webs to yield resiliently under the influence of the greater heat to which the head of the iston is subjected; l

These features of construction are highly important in the present invention and when em odied in a piston of the ty'pe disclosed obtain highly satisfactory results. These features avoid the binding of the piston in the cylinder which sometimes occurs in the case of istons having transverse webs, as distingulshed from the arcuate connecting webs 6.

I am aware that the construction may be varied within equivalent limits Without departure from the nature and principle of the f piston is permitted to expand 4more properly under the influence of heat sides, and having webs having invention and I do not restrict myself unessentially.

What I claim and desire to secure by Letters Patent is 1. A piston, comprising a head, a skirt circumferentially separated from the :head and having two diametrically opposite openings extending downwardly from its upper en and having slots extending upwardly from its lower end and terminating above the plane of the lower ends of said openings and below the upper end of the skirt, and inwardly pro]ecting webs connecting the lower portion of the skirt'in the vertical planes of the lower ends of said openings with said head above said openings and adapted to support a piston pin.

2. A piston, comprising a head, a skirt circumferentially disconnected from the head having diainetrically opposite openingsextending downwardly from its upper end having slots extending upwardly from its lower end and terminating at oints below the upper end of the Vskirt an above the plane of the lower edges ofsaid openings, and webs forming integral connections between the head and the skirt in line with said openings.

3. A piston, comprising a head, a skirt circumferentially separate from the head and having openings extending downwardly from its upper end at diametrically opposite sides and having slots between said openings extending from the lower ends of the skirt approximately one-half and less than the entire length thereof, and webs having their` lower ends integrally united with said skirt in the vertical planes of said openings and having their upper ends integrally united with said head.

4. A piston, comprising a head, a skirt circumferentially separate Jfrom having openings extending downwardly from its upper end at diametrically opposite slots between said openings extending from the lower ends of the skirt approximately one half and less than the entire length thereof and terminating above the plane of the lower ends of said openings, their lower ends integrally united with said skirt below said openings and having their upper ends integrally united with said head, and piston pin bosses supported by said webs and having their outer ends substantially within the circumference of the skirt.

5. A piston, comprising a head having a number of circumferential grooves adapted to receive piston rings, a skirt circumferentially disconnected from the head and having a splitA lower portion and having openings extending downwardly from its upper end to a plane below the upper end of said split portion, and webs having their lower ends integrally united with the skirt below said the head and ALampes.

openings and havingl their upper ends integrally united with said head.

6. A piston comprising a cup-like head having a circumferential groove adapted to receive a piston ring, av skirt circumferentially disconnected from ing a slit extending upwardly from its lower end and having openings extending downwardly from its upper end at diametrically opposite sides, we s integrally united with said skirt below said openings and extending upwardly and inwardly and having their upper ends extending outwardly and integrally connected withthe lowerportion of said cuplike head, and piston pin bosses integral with said webs. v

75 In a piston, a head, a skirt circumerentially disconnected from the head and having diametrically opposite openings extending downwardly from the upper end, approximately U-shaped webs each having its lower end integrally united with the piston below one of said openings and its upper end integrally united with the head, and piston pin bosses within the U ofsaid webs and having their outer ends .within the circumference of the skirt. l

8. In a piston, a head, a skirt circumferentially disconnected from the head and having diametrically opposite openings extending from the upper end downwardly more than one halt` of the length of the skirt, and slits extending upwardly from its lower end more than one-half and less than the entire length of the skirt, webs having their lower ends integrally united with the piston below said openings and their upper ends integrally united with the head, and piston pin bosses on the outer sides of said webs and having their outer ends within the circumference of the skirt.

STEPHEN D. HARTOG.

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